From 40c4162df6766fb1e8ede875ca8df25d8075d3a5 Mon Sep 17 00:00:00 2001 From: Joseph Myers Date: Mon, 18 Dec 2017 22:55:28 +0000 Subject: Disable -Wrestrict for two nptl/tst-attr3.c tests. nptl/tst-attr3 fails to build with GCC mainline because of (deliberate) aliasing between the second (attributes) and fourth (argument to thread start routine) arguments to pthread_create. Although both those arguments are restrict-qualified in POSIX, pthread_create does not actually dereference its fourth argument; it's an opaque pointer passed to the thread start routine. Thus, the aliasing is actually valid in this case, and it's deliberate in the test. So this patch makes the test disable -Wrestrict for the two pthread_create calls in question. (-Wrestrict was added in GCC 7, hence the __GNUC_PREREQ conditions, but the particular warning in question is new in GCC 8.) Tested compilation with build-many-glibcs.py for aarch64-linux-gnu. * nptl/tst-attr3.c: Include . (do_test) [__GNUC_PREREQ (7, 0)]: Ignore -Wrestrict for two tests. --- nptl/tst-attr3.c | 19 +++++++++++++++++++ 1 file changed, 19 insertions(+) (limited to 'nptl') diff --git a/nptl/tst-attr3.c b/nptl/tst-attr3.c index bc23386daf..420a7dba8b 100644 --- a/nptl/tst-attr3.c +++ b/nptl/tst-attr3.c @@ -26,6 +26,7 @@ #include #include +#include static void * tf (void *arg) @@ -362,7 +363,16 @@ do_test (void) result = 1; } + DIAG_PUSH_NEEDS_COMMENT; +#if __GNUC_PREREQ (7, 0) + /* GCC 8 warns about aliasing of the restrict-qualified arguments + passed &a. Since pthread_create does not dereference its fourth + argument, this aliasing, which is deliberate in this test, cannot + in fact cause problems. */ + DIAG_IGNORE_NEEDS_COMMENT (8, "-Wrestrict"); +#endif err = pthread_create (&th, &a, tf, &a); + DIAG_POP_NEEDS_COMMENT; if (err) { error (0, err, "pthread_create #2 failed"); @@ -388,7 +398,16 @@ do_test (void) result = 1; } + DIAG_PUSH_NEEDS_COMMENT; +#if __GNUC_PREREQ (7, 0) + /* GCC 8 warns about aliasing of the restrict-qualified arguments + passed &a. Since pthread_create does not dereference its fourth + argument, this aliasing, which is deliberate in this test, cannot + in fact cause problems. */ + DIAG_IGNORE_NEEDS_COMMENT (8, "-Wrestrict"); +#endif err = pthread_create (&th, &a, tf, &a); + DIAG_POP_NEEDS_COMMENT; if (err) { error (0, err, "pthread_create #3 failed"); -- cgit 1.4.1